Khmelevskij, Yu. I. Equations in a free semigroup. (Russian) Zbl 0224.02037 Tr. Mat. Inst. Steklova 107, 286 S. (1971). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 2 Documents MSC: 20M05 Free semigroups, generators and relations, word problems PDF BibTeX XML OpenURL